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Journal of veterinary internal medicine2015; 29(3); 932-939; doi: 10.1111/jvim.12595

Gallium maltolate as an alternative to macrolides for treatment of presumed Rhodococcus equi pneumonia in foals.

Abstract: Macrolide-resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials. Objective: The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment. Methods: Fifty-four foals with subclinical pulmonary abscesses among 509 foals at 6 breeding farms in Kentucky. Methods: Controlled, randomized, prospective noninferiority study. Foals with ultrasonographic lesions >1 cm in diameter (n = 54) were randomly allocated to receive per os either clarithromycin combined with rifampin (CLR+R) or GaM, and followed up for 28 days by daily physical inspections and weekly (n = 1 farm) or biweekly (n = 4 farms) thoracic ultrasound examinations by individuals unaware of treatment-group assignments. Treatment success was defined as resolution of ultrasonographically identified pulmonary abscesses within 28 days of initiating treatment. Noninferiority was defined as a 90% confidence interval for the observed difference in CLR+R minus GaM that was ≤10%. Results: The proportion of GaM-treated foals that resolved (70%; 14/20) was similar to that of foals treated with CLR+R (74%; 25/34), but we failed to demonstrate noninferiority for GaM relative to CLR+R; however, GaM was noninferior to CLR+R treatment when results from a noncompliant farm were excluded. Conclusions: Gallium maltolate is not inferior to macrolides for treating foals with subclinical pneumonia. Use of GaM might reduce pressure for macrolide-resistance in R. equi.
Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
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Publication Date: 2015-04-13 PubMed ID: 25868480PubMed Central: PMC4895420DOI: 10.1111/jvim.12595Google Scholar: Lookup
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  • Journal Article
  • Randomized Controlled Trial
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article looks at the effectiveness of gallium maltolate(GaM) as an alternative treatment to macrolides in managing pneumonia presumed to be caused by Rhodococcus equi in foals. The study aimed to prove that GaM was no more than 10% less effective than the standard macrolide treatment.

Objective and Methods of the Research

  • The primary objective of the study was to analyze if the rate of successful treatment with GaM in foals that have ultrasonographic signs of pneumonia, thought to be caused by Rhodococcus equi, was not more than 10% lower than the foals who were treated with standard treatment.
  • The study was a controlled, randomized, noninferiority study carried out on 54 foals with subclinical pulmonary abscesses selected randomly from 509 foals from six breeding farms in Kentucky. The selected foals had ultrasonographic lesions of more than 1 cm in diameter.
  • The foals were randomly given oral clarithromycin combined with rifampin (CLR+R), the standard treatment, or GaM, the alternative treatment, and observed for 28 days with daily physical inspections and weekly or biweekly thoracic ultrasound by individuals who were unaware of the treatments given to the foals.
  • The success was defined as the resolution of the pulmonary abscesses identified ultrasonographically within the 28 days of starting the treatment.
  • Noninferiority for GaM relative to CLR+R was defined as a 90% confidence interval for the observed difference where CLR+R minus GaM was less than or equal to 10%.

Results of the Study

  • The study showed a similar proportion of successful treatment for both the GaM (70%) and CLR+R (74%) treated foals.
  • However, the study could not conclusively prove noninferiority for GaM treatment when compared to CLR+R.
  • Though when the data from a farm that didn’t adhere to the protocol was excluded, GaM treatment was shown to be noninferior to the standard CLR+R treatment.

Conclusion of the Research

  • The research concluded that GaM is not inferior to macrolides in the treatment of foals with subclinical pneumonia.
  • The use of GaM, instead of macrolides, could reduce the pressure for macrolide-resistance in R. equi.

Cite This Article

APA
Cohen ND, Slovis NM, Giguère S, Baker S, Chaffin MK, Bernstein LR. (2015). Gallium maltolate as an alternative to macrolides for treatment of presumed Rhodococcus equi pneumonia in foals. J Vet Intern Med, 29(3), 932-939. https://doi.org/10.1111/jvim.12595

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 29
Issue: 3
Pages: 932-939

Researcher Affiliations

Cohen, Noah D
  • Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX.
Slovis, Nathan M
  • McGee Medicine Center, Hagyard Equine Medical Institute, Lexington, KY.
Giguère, Steeve
  • Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA.
Baker, Samantha
  • McGee Medicine Center, Hagyard Equine Medical Institute, Lexington, KY.
Chaffin, M Keith
  • Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX.
Bernstein, Lawrence R
  • Terrametrix, Menlo Park, CA.

MeSH Terms

  • Actinomycetales Infections / drug therapy
  • Actinomycetales Infections / microbiology
  • Actinomycetales Infections / veterinary
  • Animals
  • Anti-Bacterial Agents / therapeutic use
  • Horse Diseases / drug therapy
  • Horse Diseases / microbiology
  • Horses
  • Organometallic Compounds / therapeutic use
  • Pneumonia, Bacterial / drug therapy
  • Pneumonia, Bacterial / microbiology
  • Pneumonia, Bacterial / veterinary
  • Pyrones / therapeutic use
  • Rhodococcus equi / drug effects

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This article includes 22 references
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Citations

This article has been cited 9 times.
  1. Álvarez-Narváez S, Huber L, Giguère S, Hart KA, Berghaus RD, Sanchez S, Cohen ND. Epidemiology and Molecular Basis of Multidrug Resistance in Rhodococcus equi. Microbiol Mol Biol Rev 2021 May 19;85(2).
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  2. Piatek M, Griffith DM, Kavanagh K. Quantitative proteomic reveals gallium maltolate induces an iron-limited stress response and reduced quorum-sensing in Pseudomonas aeruginosa. J Biol Inorg Chem 2020 Dec;25(8):1153-1165.
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  3. Rakowska A, Cywinska A, Witkowski L. Current Trends in Understanding and Managing Equine Rhodococcosis. Animals (Basel) 2020 Oct 18;10(10).
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  4. Álvarez-Narváez S, Berghaus LJ, Morris ERA, Willingham-Lane JM, Slovis NM, Giguere S, Cohen ND. A Common Practice of Widespread Antimicrobial Use in Horse Production Promotes Multi-Drug Resistance. Sci Rep 2020 Jan 22;10(1):911.
    doi: 10.1038/s41598-020-57479-9pubmed: 31969575google scholar: lookup
  5. Rocha JN, Dangott LJ, Mwangi W, Alaniz RC, Bordin AI, Cywes-Bentley C, Lawhon SD, Pillai SD, Bray JM, Pier GB, Cohen ND. PNAG-specific equine IgG(1) mediates significantly greater opsonization and killing of Prescottella equi (formerly Rhodococcus equi) than does IgG(4/7). Vaccine 2019 Feb 21;37(9):1142-1150.
    doi: 10.1016/j.vaccine.2019.01.028pubmed: 30691984google scholar: lookup
  6. Giacani L, Bernstein LR, Haynes AM, Godornes BC, Ciccarese G, Drago F, Parodi A, Valdevit S, Anselmi L, Tomasini CF, Baca AM. Topical treatment with gallium maltolate reduces Treponema pallidum subsp. pertenue burden in primary experimental lesions in a rabbit model of yaws. PLoS Negl Trop Dis 2019 Jan;13(1):e0007076.
    doi: 10.1371/journal.pntd.0007076pubmed: 30601824google scholar: lookup
  7. Oyama MA, Ellenberg SS, Shaw PA. Clinical Trials in Veterinary Medicine: A New Era Brings New Challenges. J Vet Intern Med 2017 Jul;31(4):970-978.
    doi: 10.1111/jvim.14744pubmed: 28557000google scholar: lookup
  8. Hardefeldt L, Thomas K, Page S, Norris J, Browning G, El Hage C, Stewart A, Gilkerson J, Muscatello G, Verwilghen D, van Galen G, Bauquier J, Cuming R, Reynolds B, Whittaker C, Wilkes E, Clulow J, Burden C, Begg L. Antimicrobial prescribing guidelines for horses in Australia. Aust Vet J 2025 Dec;103(12):781-889.
    doi: 10.1111/avj.70003pubmed: 40903020google scholar: lookup
  9. Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA. Antimicrobial Resistance in Equines: A Growing Threat to Horse Health and Beyond-A Comprehensive Review. Antibiotics (Basel) 2024 Jul 29;13(8).
    doi: 10.3390/antibiotics13080713pubmed: 39200013google scholar: lookup
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